Merge "Cache window and icon color of splash screen starting window" into...

Merge "Cache window and icon color of splash screen starting window" into sc-dev am: 00d26d71 am: 7977ff6a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14842877

Change-Id: Icb7e773fb81b4a300acb0ecc5a26752f51ec4e32